Thin fragmental titanium oxide and porous body as an aggregate thereof, and methods for their production

Abstract

Titanium oxide, comprising lamina shaped titanium oxide particles having a thickness of 10-30 nm and a width of 0.5 to 1 μm, may be prepared by exfoliating a layered titanic acid powder having a formula H x Ti 2-x/4 O 4 .nH 2 O, where x=0.60-0.75, to form a titania sol; followed by drying and heating, to obtain a titanium oxide. The layered titanic acid powder may be prepared by contacting cesium titanate having an orthorhombic layered structure with an aqueous acid solution.

What is claimed is: 
     
       1. A titanium oxide porous body consisting essentially of an aggregate of lamina shaped titanium oxide particles having a thickness of 10-30 nm and a width of 0.5 to 1 μm, the titanium oxide porous body having a specific surface area of from 40 to 110 m 2  /g and a surface characteristic of meso pores and macro pores having a pore size of from 2 to 100 nm. 
     
     
       2. A method for producing the titanium oxide porous body of claim 1, the method comprising: drying a titania sol comprising lamina shaped titanium oxide particles having a thickness of 10-30 nm and a width of 0.5 to 1 μm; and   heating the dried titania sol, thus   producing the titanium oxide porous body.   
     
     
       3. The method of claim 2, wherein the drying is vacuum freeze drying. 
     
     
       4. The method of claim 2, wherein the lamina shaped titanium oxide particles are produced by a method comprising: exfoliating a layered titanic acid powder having a formula   H.sub.x Ti.sub.2-x/4 O.sub.4.nH.sub.2 O     where x=0.60-0.75, to form a titania sol, followed by     heating the titania sol, to obtain the lamina shaped titanium oxide particles.   
     
     
       5. The method of claim 2, wherein the lamina shaped titanium oxide particles are produced by a method comprising: contacting cesium titanate having an orthorhombic layer structure (Cs x  Ti 2-x/4  O 4 , x=0.60-0.75) with an aqueous acid solution to form a layered titanic acid powder having a H x  Ti 2-x/4  O 4 .nH 2  O composition,   mixing and stirring the powder with an aqueous amine solution to form a titania sol,   drying the resulting titania sol, followed by   heating the dried titania sol to obtain the lamina shaped titanium oxide having a thin fragmental shape.